Evaluation on Assimilation Application of Yunhai-2 Occultation Data in Regional Numerical Weather Prediction Model
-
摘要: 针对中国自主的云海-2掩星资料，基于WRF模式和GSI三维变分同化系统，以2019年5月首次开展了区域同化预报试验，试验结果表明：同化云海-2掩星资料后，风场、温度场的改善主要体现在预报的中后期，而湿度场的改善则贯穿于整个预报时间段，风场、温度场和湿度场的改善程度随着预报时间延长趋于一致；风场和温度场的改善主要体现在模式中层，而水汽混合比的改善则主要体现在模式的中低层；同化云海-2掩星资料能够合理的调整模式的位势高度场、湿度场、温度场和风场，进而改善降水预报结果。Abstract: Based on the WRF (Weather Research and Forecasting) model and GSI (Gridpoint Statistical Interpolation analysis system) three-dimensional variational assimilation system, regional assimilation and prediction experiments for China’s autonomic Yunhai-2 occultation data were performed for the first time in May 2019. The results of the experiments demonstrated that after assimilating Yunhai-2 occultation data, the improvement for the wind and temperature fields is mainly reflected in the middle and later stages of the forecast, while the improvement for the humidity field is witnessed through the entire forecast period. The results also showed that the improvement degree of the wind, temperature, and humidity fields tends to be consistent with the extension of forecast time. It was found that the improvement for the wind and temperature fields is mainly reflected in the middle layer of the model, while the improvement for the water vapor mixing ratio is mainly reflected in the middle and lower layers of the model. Thus, assimilating Yunhai-2 occultation data can reasonably adjust the potential height, humidity, temperature, and wind fields in the model, thereby improving the precipitation forecast results.
-
图 3 试验YHDA相对于试验CTRL的（a）U（单位：m s−1）、（b）V（单位：m s−1）、（c）温度场T（单位：K）和（d）水汽混合比（单位：g kg−1）预报场降低的均方根误差
Figure 3. Root mean square errors (RMSE) of the decrease for experiment YHDA (the assimilation of yunhai-2 occultation data is added on the basis of the experiment CTRL) forecast relative to experiment CTRL (Only conventional observation data were assimilated): (a) Zonal wind U (units: m s−1); (b) meridinal V (units: m s−1); (c) temperature T (units: K); (d) water vapor mixing ratio Qv (units: g kg−1)
图 4 试验YHDA相对于试验CTRL各要素场预报均方根误差降低百分比
Figure 4. Decrease percentage of RMSE for experiment YHDA prediction relative to experiment CTRL
图 5 试验YHDA相对于试验CTRL在模式层上（a）U（单位：m s−1）、（b）V（单位：m s−1）、（c）温度场（单位：K）和（d）水汽混合比（单位：g kg−1）24 h预报降低的均方根误差分布
Figure 5. RMSE distributions of the decrease in the 24-h forecast for experiment YHDA relative to experiment CTRL on model levels: (a) U (units: m s−1); (b) V (units: m s−1); (c) T (units: K); (d) Qv (units: g kg−1)
图 8 2019年5月25日08时到5月26日08时中国降水量（单位：mm）实况
Figure 8. Precipitation (units: mm) observation for China from 0800 BJT (Beijing time) 25 May to 0800 BJT 26 May 2019
图 9 2019年5月25日08时（起报时刻）到5月26日08时中国降水量（单位：mm）的48 h预报：（a）试验CTRL；（b）试验YHDA
Figure 9. 48-h prediction of precipitation (units: mm) for China from 0800 BJT on 25 May to 0800 BJT on 26 May 2019: (a) Experiment CTRL; (b) experiment YHDA
图 10 2019年5月25日08时500 hPa位势高度场（单位：gpm）：（a）NCEP再分析场（0.25°×0.25°）；（b）试验CTRL、（c）试验YHDA的24 h预报场
Figure 10. 500-hPa geopotential height field (units: gpm) at 0800 BJT on 25 May 2019: (a) NCEP reanalysis data (0.25°×0.25°); the 24-h prediction fields for (b) experiment CTRL, (c) experiment YHDA
图 11 2019年5月25日08时试验YHDA相对于试验CTRL的700 hPa比湿增量场（彩色阴影）和温度增量场（黑色等值线，单位：K）
Figure 11. Specific humidity increment field (color shadings) and temperature increment field (black contours, units: K) at 700 hPa for experiment YHDA relative to experiment CTRL at 0800 BJT on 25 May 2019
图 12 2019年5月25日08时试验YHDA相对于试验CTRL的700 hPa风场增量（箭头，单位：m s−1）和散度场增量（彩色阴影，单位：10−4 s−1）
Figure 12. Wind increment field (vectors, units: m s−1) and divergence increment field (color shadings, units: 10−4 s−1) at 700 hPa for experiment YHDA relative to experiment CTRL at 0800 BJT on 25 May 2019
-
[1] Anthes R A, Rocken C, Kuo Y H. 2000. Applications of COSMIC to meteorology and climate [J]. Terrestrial, Atmospheric and Oceanic Sciences, 11(1): 115−156. doi: 10.3319/TAO.2000.11.1.115(COSMIC) [2] Cucurull L. 2010. Improvement in the use of an operational constellation of GPS radio occultation receivers in weather forecasting [J]. Wea. Forecasting, 25(2): 749−767. doi: 10.1175/2009WAF2222302.1 [3] Healy S B, Jupp A M, Marquardt C. 2005. Forecast impact experiment with GPS radio occultation measurements [J]. Geophys. Res. Lett., 32(3): L03804. doi: 10.1029/2004GL020806 [4] Healy S B, Thépaut J N. 2006. Assimilation experiments with CHAMP GPS radio occultation measurements [J]. Quart. J. Roy. Meteor. Soc., 132(615): 605−623. doi: 10.1256/qj.04.182 [5] Huang C Y, Kuo Y H, Chen S H, et al. 2005. Improvements in typhoon forecasts with assimilated GPS occultation refractivity [J]. Wea. Forecasting, 20(6): 931−953. doi: 10.1175/WAF874.1 [6] Kuo Y H, Zou X, Huang W. 1998. The impact of Global Positioning System data on the prediction of an extratropical cyclone: An observing system simulation experiment [J]. Dyn. Atmos. Oceans, 27(1−4): 439−470. doi: 10.1016/S0377-0265(97)00023-7 [7] 马再忠, 郭英华, 王斌. 2011. GPS掩星观测的发展及其在气象业务中的应用现状 [J]. 气象学报, 69(1): 208−218. doi: 10.11676/qxxb2011.018Ma Zaizhong, Kuo Y H, Wang Bin. 2011. The GPS radio occultation data and its current operational applications to the numerical weather prediction [J]. Acta Meteor. Sinica (in Chinese), 69(1): 208−218. doi: 10.11676/qxxb2011.018 [8] 王挺, 项杰, 寇正, 等. 2015. 掩星折射率和弯角同化对台风预报影响的对比 [J]. 解放军理工大学学报, 16(3): 260−265.Wang Ting, Xiang Jie, Kou Zheng, et al. 2015. Comparison of impact of GPS RO refractivity and bending angle data assimilation for typhoon prediction [J]. Journal of PLA University of Science and Technology (Natural Science Edition) (in Chinese), 16(3): 260−265. [9] 余江林, 寇正, 项杰, 等. 2014. 掩星弯角资料同化在一次暴雨过程中的应用 [J]. 暴雨灾害, 33(2): 181−186. doi: 10.3969/j.issn.1004-9045.2014.02.011Yu Jianglin, Kou Zheng, Xiang Jie, et al. 2014. Application of GPS bending angle data assimilation in a rainstorm event [J]. Torrential Rain and Disasters (in Chinese), 33(2): 181−186. doi: 10.3969/j.issn.1004-9045.2014.02.011 [10] 朱孟斌. 2012. GPS无线电掩星资料同化技术研究 [D]. 国防科学技术大学硕士学位论文.Zhu Mengbin. 2012. Research on GPS radio occultation data assimilation [D]. M. S. thesis (in Chinese), National University of Defense Technology. [11] 朱孟斌, 张卫民, 曹小群. 2013. GPS掩星一维弯曲角算子在四维变分资料同化系统中的实现方法研究 [J]. 物理学报, 18(62): 189203. doi: 10.7498/aps.62.189203Zhu Mengbin, Zhang Weimin, Cao Xiaoqun. 2013. Research on the implementation of GPS radio occultation one-dimensional bending angle operator in four-dimensional variational data assimilation system [J]. Acta Phys. Sinica (in Chinese), 18(62): 189203. doi: 10.7498/aps.62.189203 [12] Zou X, Kuo Y H, Guo Y R. 1995. Assimilation of atmospheric radio refractivity using a nonhydrostatic adjoint model [J]. Mon. Wea. Rev., 123(7): 2229−2250. doi:10.1175/1520-0493(1995)123<2229:AOARRU>2.0.CO;2 [13] 邹逸航, 马旭林, 姜胜, 等. 2017. COSMIC掩星资料同化对台风“天兔”预报影响的试验 [J]. 海洋学研究, 35(3): 9−19. doi: 10.3969/j.issn.1001-909X.2017.03.002Zou Yihang, Ma Xulin, Jiang Sheng, et al. 2017. Effect of COSMIC occultation data assimilation on prediction of typhoon Usagi [J]. Journal of Marine Sciences (in Chinese), 35(3): 9−19. doi: 10.3969/j.issn.1001-909X.2017.03.002 -
下载:
点击查看大图
计量
- 文章访问数: 13
- HTML全文浏览量: 0
- PDF下载量: 2
- 被引次数: 0
